DokuWiki is a standards-compliant, simple-to-use
Wiki mainly aimed at creating documentation of any
kind. It is targeted at developer teams,
workgroups, and small companies. It has a simple
but powerful syntax which makes sure the datafiles
remain readable outside the Wiki, and eases the
creation of structured texts. All data is stored
in plain text files, so no database is needed

Tiki Wiki CMS Groupware is a full-featured, Web-based, multilingual, tightly integrated, all-in-one wiki, CMS, and groupware. Tiki can be used to create all kinds of Web applications, sites, portals, knowledge bases, intranets, and extranets. Tiki offers a very large number of features "out-of-the-box". It is highly configurable and modular. All features are optional and administered via a Web-based interface. Major features include a robust wiki engine, news articles, discussion forums, newsletters, blogs, file and image galleries, bug and issue trackers, a link directory, polls/surveys and quizzes, FAQs, a banner management system, calendar, maps, mobile access, RSS feeds, a category system, tags, an advanced themeing engine (Smarty), spreadsheet, live support, shoutbox, inter-user messaging, menu generator, advanced permission system for users and groups, internal search engine, external authentication support, and more. It was formerly named TikiWiki.

The Advanced Bash Scripting Guide is both a reference and a tutorial on shell scripting. This comprehensive book, the equivalent of 1,000+ print pages, covers almost every aspect of shell scripting. It contains 382 profusely commented illustrative examples, a number of tables, and a cross-linked index/glossary. Not just a shell scripting tutorial, this book also provides an introduction to basic programming techniques, such as sorting and recursion. Included scripts are the Game of Life, a Perquackey variant, a Morse code trainer, and an implementation of the Gronsfeld Cipher. This book is suited for both individual study and classroom use. It covers Bash, up to and including version 4.2.
Note that users of miniaturized single-board computers
running Linux, such as the Raspberry Pi and the Beagle
Bone, would find this Guide useful for learning and running Bash scripts to explore and expand the capabilities of these small, but powerful machines.

A WikiWikiWeb is a collaborative hypertext environment, with an emphasis on easy access to and modification of information. MoinMoin is a Python WikiClone that allows you to easily set up your own wiki, only requiring a Web server and a Python installation.

Doxygen is a cross-platform, JavaDoc-like
documentation system for C++, C, Objective-C, C#,
Java, IDL, Python, PHP, VHDL, and Fortran. Doxygen
can be used to generate an on-line class browser
(in HTML) and/or an off-line reference manual (in
LaTeX or RTF) from a set of source files. Doxygen
can also be configured to extract the
code-structure from undocumented source files.
This includes dependency graphs, class diagrams
and hyperlinked source code. This type of
information can be very useful to quickly find
your way in large source distributions.

LyX is a document processor that encourages an approach to writing based on the structure of your documents, not their appearance. It is intended for people people who write and want their writing to look great without tinkering with formatting details, font attributes, or page boundaries. On screen, it looks like any word processor, but it uses the TeX engine for printed output and producing richly cross-referenced PDFs. It is stable and fully featured.

GNU TeXmacs is a free wysiwyw (what you see is what you want) editing platform with special features for scientists. The software aims to provide a unified and user friendly framework for editing structured documents with different types of content: text, mathematics, graphics, interactive content. TeXmacs can also be used as an interface to many external systems for computer algebra, numerical analysis, and statistics. New presentation styles can be written by the user and new features can be added to the editor using Scheme.

OpenDocMan is a full featured Web-based document management system (DMS) designed to conform to ISO 17025/IEC. It features an automated installation script, custom themes, plugins, check-in/out, departmental access control, file moderation, fine grained user access control, and a great search function. Written in PHP, and utilizing MySQL for the backend, this project is useful for any company looking to keep their documentation in a centralized repository.

ArgoUML is a pure Java open source UML CASE tool that provides cognitive support for object-oriented design. ArgoUML provides some of the same editing and code generation features of a commercial CASE tool, but it focuses on features that enhance usability and support the cognitive needs of designers. Uses XML file formats: XMI and PGML.